Toxoplasma Gondii (Amniotic Fluid)
Does this test have other names?
Polymerase chain reaction (PCR) for Toxoplasma gondii DNA
What is this test?
This test is used to diagnose Toxoplasma gondii (T. gondii) infection in the fetus. T.
gondii is a parasite that can infect people, but infections often don't cause any
symptoms. People can become infected after eating infected undercooked meat, especially
lamb, venison, or pork, or drinking contaminated water. People can also be exposed
to the parasite by cleaning a cat litter box when the cat has shed the parasite in
This disease is of particular concern to pregnant women. If a woman becomes infected
with the parasite for the first time while she is pregnant, the infection can travel
to the fetus. This can lead to birth defects such as brain damage and serious eye
problems. Children who appear unaffected at birth may still develop problems later
in life. Women who are infected before they become pregnant only rarely pass the disease
to their unborn babies.
Why do I need this test?
You might have this test if you're pregnant and your healthcare provider strongly
suspects that you have a new T. gondii infection. The results can help guide treatments
that may help keep your baby from having health problems.
What other tests might I have along with this test?
Your healthcare provider may want to test you for antibodies called IgM and IgG, which
your immune system makes against this parasite. These can help find out whether you
have been infected during pregnancy. Your blood may also be tested to look for this
The provider may also want to examine the fetus with a CT scan or ultrasound.
What do my test results mean?
A result for a lab test may be affected by many things, including the method the laboratory
uses to do the test. If your test results are different from the normal value, you
may not have a problem. To learn what the results mean for you, talk with your healthcare
If your results are negative, you and your fetus don't have an infection. A positive
result means that you and your fetus have T. gondii.
How is this test done?
This test requires taking a sample of the amniotic fluid that surrounds the fetus
by doing an amniocentesis. Using ultrasound as a guide, your healthcare provider will
put a long needle into your abdomen and into the uterus. He or she will withdraw amniotic
fluid to be tested.
Does this test pose any risks?
Risks from the amniocentesis procedure include:
Cramping and discomfort
Vaginal bleeding in the mother
Leakage of amniotic fluid afterward
Miscarriage, which occurs in about one in every 300 to 500 procedures
Also, if you have hepatitis, HIV, or another chronic infection, it may infect the
What might affect my test results?
The PCR test is not able to find T. gondii DNA in amniotic fluid if you develop antibodies
against the parasite during your first trimester.
How do I get ready for this test?
Ask your healthcare provider whether you should take any special steps to prepare
for this test.